Slurry catalyst compositions, means for their preparation and their use in hydroprocessing of heavy feeds are known in the refining arts. Some examples are discussed below:
U.S. Pat. No. 4,710,486 discloses a process for the preparation of a dispersed Group VIB metal sulfide hydrocarbon oil hydroprocessing catalyst. Process steps include reacting aqueous ammonia and a Group VIB metal compound, such as molybdenum oxide or tungsten oxide, to form a water soluble oxygen-containing compound such as ammonium molybdate or tungstate.
U.S. Pat. No. 4,970,190 discloses a process for the preparation of a dispersed Group VIB metal sulfide catalyst for use in hydrocarbon oil hydroprocessing. This catalyst is promoted with a Group VIII metal. Process steps include dissolving a Group VIB metal compound, such as molybdenum oxide or tungsten oxide, with ammonia to form a water soluble compound such as aqueous ammonium molybdate or ammonium tungstate.
U.S. Pat. No. 5,053,376 discloses a process for preparing a sulfided molybdenum catalyst concentrate. A precursor catalyst concentrate is formed by mixing together: (i) a hydrocarbonaceous oil comprising constituents boiling above about 1050 degree F.; (ii) a metal compound selected from the group consisting of Groups II, III, IV, V, VIB, VIIB, and VIII of the Periodic Table of the Elements, in an amount to provide from about 0.2 to 2 wt. % metal, based on the hydrocarbonaceous oil; and (iii) elemental sulfur in an amount such that the atomic ratio of sulfur to metal is from about 1/1 to 8/1 then (b) heating the mixture to an effective temperature to product a catalyst concentrate. Ammonium compounds may also be used in the preparation process.
In the preparation of slurry catalysts such as those discussed above, it is possible to produce ammonium sulfate as a waste product.